#include <iostream>
using namespace std;
void f(int&num,char oper);
int main()
{
    int numero=5;
    f(num,'+');
    cout<<num;
}
void f(int&num,char oper)
{
    if (oper=='+')
    num++;
    else if(oper=='-')
    num--;
    return;
}
